1. Field of the Invention
The present invention is generally related to a fuel system for a marine vessel and, more particularly, to a fuel system in which a pump and regulator is attached to an external surface of the fuel tank of the marine vessel.
2. Description of the Prior Art
Many different types of fuel systems are well known for use in conjunction with marine propulsion systems associated with marine vessels.
U.S. Pat. No. 6,253,742, which issued to Wickman et al on Jul. 3, 2001, discloses a fuel supply method for a marine propulsion engine. A method for controlling the operation of a fuel system of an outboard motor uses a lift pump to transfer fuel from a remote tank to a vapor separator tank. Only one level sensor is provided in the vapor separator tank and an engine control unit monitors the total fuel usage subsequent to the most recent filling of the tank. When the fuel usage indicates that the fuel level in the vapor separator tank has reached a predefined lower level, a lift pump is activated to draw fuel from a remote tank and provide that fuel to the vapor separator tank.
U.S. Pat. No. 6,109,243, which issued to Seyerle on Aug. 29, 2000, describes a marine fuel tank pump. The pump comprises a container for assembly into a marine fuel tank. An electric fuel pump is housed in the container. The pump has an inlet receiving fuel from the tank and an outlet. A pressure release is operatively associated with the outlet for releasing pressure from the outlet into the fuel tank when the pump is de-energized.
U.S. Pat. No. 6,102,011, which issued to Meyer et al on Aug. 15, 2000, describes an in-tank fuel delivery system for marine vessels. A fuel delivery system used on marine vessels has a fuel injected, internal combustion engine for propulsion. A fuel tank stores fuel supplied to run the engine through a supply line extending between the fuel tank and the engine. The tank has a relatively small opening, and a fuel pump is sized to fit within the fuel tank through this opening. The fuel pump pumps fuel, under pressure, from the fuel tank to the engine. A fuel filter is also sized to fit within the tank and is connected to an inlet of the fuel pump. Fuel is drawn into the fuel pump through the fuel filter. A pressure regulator regulates the pressure of fuel pumped to the engine. The pressure regulator is mounted externally of the tank and the fuel pump is tethered to the pressure regulator for the fuel pump and fuel filter to be installed in the fuel tank without use of external supporting structure.
U.S. Pat. No. 6,056,028, which issued to Crawford on May 2, 2000, describes a potable fueling apparatus. The device is described wherein fuel is dispensed directly from the vehicle fuel tank by the vehicle fuel pump through the hose of the invention so that a supply of gasoline can be provided for auxiliary engines such as boat, lawn mowers, and the like. A Schrader valve is provided in the fuel line and the portable device of this invention includes a coupling for opening the Schrader valve the end of the hose and a nozzle at the opposite end.
U.S. Pat. No. 5,913,294, which issued to Takahashi et al on Jun. 22, 1999, describes an outboard motor fuel supply system. An outboard motor for a watercraft includes a simply structured fuel supply system of a smaller size and a longer life than prior fuel supply systems. The fuel supply system includes a delivery fuel tank carried by the outboard motor. Fuel is pumped from an external fuel supply tank carried by the watercraft to the delivery fuel tank by a low pressure fuel pump located within the outboard motor. A control system controls the low pressure fuel pump so that a predetermined level of fuel is maintained in the delivery fuel tank. The control system includes a fluid level detection sensor that detects the level of fuel within the delivery fuel tank and produces a corresponding signal indicative of the fuel level. A control unit circuit receives the fluid level signal and determines if the fluid level in the tank is higher or lower than a predetermined maximum fuel level. If the fuel level is determined to be higher than a maximum fuel level, the control unit circuit deactivates the low pressure fuel pump. If the fuel level is determined to be lower than the maximum fuel level, the control unit circuit activates the low pressure fuel pump.
U.S. Pat. No. 5,389,245, which issued to Jaeger et al on Feb. 14, 1995, discloses a vapor separating unit for a fuel system. The vapor separating unit has a particular application to a fuel system for a marine engine. The vapor separating unit includes a closed tank having a fuel inlet through which fuel is fed to the tank by a diaphragm pump. The liquid level in the tank is controlled by a float operated valve. An electric pump is located within the vapor separating tank and has an inlet disposed in the tank and an outlet connected to a fuel rail assembly of the engine. Excess fuel from the fuel rail assembly is conducted back to the upper end of the vapor separating tank. A vapor venting mechanism is incorporated in the tank to vent vapor from the tank.
U.S. Pat. No. 4,848,283, which issued to Garms et al on Jul. 18, 1989, discloses a marine engine with a combination vapor return, crankcase pressure, and cooled fuel line conduit. A marine propulsion system includes a two cycle water cooled crankcase compression internal combustion engine including a vapor separator, a remote fuel tank, and a fuel pump in the tank for delivering fuel to the engine in response to crankcase pulse pressure. A combination conduit between the fuel tank and the engine includes a first passage communicating crankcase pulse pressure from the engine to the fuel pump in the tank, a second passage supplying fuel from the pump in the tank to the engine, a third passage returning fuel vapor from the vapor separator at the engine back to the tank, a fourth passage supplying cooling water from the engine towards the tank, and a fifth passage returning water from the fourth passage back to the engine.
U.S. Pat. No. 6,250,287, which issued to Wickman et al on Jun. 26, 2001, discloses a fuel delivery system for a marine engine. A fuel pump is housed within the structure of a portable fuel tank. The inlet of the pump is located at the lower portion of the tank and an outlet of the pump is connectable in fluid communication with a flexible conduit. An opposite end of the flexible conduit is connectable in fluid communication with the fuel system of an outboard motor. A water sensor and a fuel level sensor can be provided in conjunction with the pump and attached to the pump in certain embodiments. A fuel pressure regulator is connected in fluid communication with the outlet of the pump and also located within the structure of the portable fuel tank.
U.S. Pat. No. 4,699,109, which issued to Hensel on Oct. 13, 1987, discloses a closed end fuel injection system. A marine fuel supply system for a fuel injected engine deadheads a high pressure fuel line with a closed end connection to the fuel injectors without a recirculating return fuel line to the fuel injection pump and without a return fuel line to the remote fuel tank. A differential pressure transducer senses differential pressure across the fuel injector between the high pressure fuel line and the low pressure induction manifold and turns off the fuel pump above a first value of relative differential pressure and turns on fuel pump at a second value below the first value, to maintain the fuel pressure in the high pressure line within a given range relative to induction manifold pressure.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.
In fuel systems for internal combustion engines, particularly in marine propulsion system applications, fuel pumps for drawing fuel from a remote fuel tank and providing that fuel to the engine are typically located either within the remote fuel tank itself or attached to and supported by the engine. In certain marine propulsion systems, such as outboard motors, the fuel pump can be located under the cowl of the outboard motor. In other types of marine propulsion systems, such as sterndrive systems and inboard systems, the fuel pump can be attached directly to the engine or within a remote fuel tank.
It would be significantly beneficial if a fuel system for a marine vessel could be provided in which the fuel pump is located close to the remote fuel tank, but not located within the tank. The placement of the fuel pump close to the remotely stored fuel allows the pump to benefit from close proximity to the liquid fuel, from the cooling temperature of the liquid fuel compared to the fuel being pumped by the fuel pump to the engine, and from the reduced likelihood that vapor lock will occur in the fuel system. It would be beneficial if such a fuel system could also avoid the inherent difficulty associated with locating the fuel pump within the remote tank itself, particularly in situations where many different suppliers of fuel tank are used and the openings formed in the wall of the fuel tank are not easily controlled in size and/or location.